import context
import time

const (
    // a reasonable duration to block in an example
    short_duration = 1 * time.millisecond
)

// This example passes a context with an arbitrary deadline to tell a blocking
// function that it should abandon its work as soon as it gets to it.
fn test_with_deadline() {
    dur := time.now().add(short_duration)
    mut background := context.background()
    mut ctx, cancel := context.with_deadline(mut background, dur)

    defer {
        // Even though ctx will be expired, it is good practice to call its
        // cancellation function in any case. Failure to do so may keep the
        // context and its parent alive longer than necessary.
        cancel()
    }

    ctx_ch := ctx.done()
    select {
        _ := <-ctx_ch {}
        1 * time.second {
            panic('This should not happen')
        }
    }
}

// This example passes a context with a timeout to tell a blocking function that
// it should abandon its work after the timeout elapses.
fn test_with_timeout() {
    // Pass a context with a timeout to tell a blocking function that it
    // should abandon its work after the timeout elapses.
    mut background := context.background()
    mut ctx, cancel := context.with_timeout(mut background, short_duration)
    defer {
        cancel()
    }

    ctx_ch := ctx.done()
    select {
        _ := <-ctx_ch {}
        1 * time.second {
            panic('This should not happen')
        }
    }
}